Theory: uses a particular frequency ultrasonic wave to repel dog
and do not have any harm to dog

Working modes:

Training the dog: turns the function changing switch (below) to the
middle-grade, and press the buttons switch beam (above), for
further information, please refer to the following article how to
telecontrol your dog

Driving the dog: when you are confronted with ferocious dogs,
please turn the function changing switch to the last grade, aim at
the ferocious dogs and press the beam button, and then the dog will
feel terrified and get away immediately

Illuminating: turns the function changing switch to the preceding
grade and press the beam button, it can be used as a torch